Resumo. Thermal modification of wood was developed in the decade of 1940 and has been largerly studied and produced in Europe. In Brazil, the research about this technique is still little and sparse, but it has gained attention nowadays. The aim of this study was to evaluate the influence of time and temperature of modification on the reduction of maximum swelling of Eucalyptus grandis wood. According to the results obtained it is possible to achieve reductions of about 50% on the maximum volumetric swelling of Eucalyptus grandis wood. The best results were obtained for 230°C of thermal modification rather than 200 °C. The factor temperature was more significant than time, once that there was no significant difference between the times used (1, 2 and 3 hours). There was no significant interaction between the factors time and temperature.